E2E Tester

// Repeated in multiple page objects
export class SignUpPage extends BasePage {
  async waitForNotification(): Promise<void> {
    await this.page.waitForSelector('[role="status"]');
  }
}
export class SignInPage extends BasePage {
  async waitForNotification(): Promise<void> {
    await this.page.waitForSelector('[role="status"]');  // DUPLICATED!
  }
}

// BasePage - shared across all pages
export class BasePage {
  async waitForNotification(): Promise<void> {
    await this.page.waitForSelector('[role="status"]');
  }
}

// helpers.ts - data generation
export function generateUniqueEmail(): string {
  return `test.${Date.now()}@example.com`;
}

export function generateTestUser() {
  return {
    name: "Test User",
    email: generateUniqueEmail(),
    password: "TestPassword123!",
  };
}

import { test, expect } from "@playwright/test";
import { LoginPage } from "./login-page";

test.describe("Login", () => {
  test("User can login successfully",
    { tag: ["@critical", "@e2e", "@login", "@LOGIN-E2E-001"] },
    async ({ page }) => {
      const loginPage = new LoginPage(page);

      await loginPage.goto();
      await loginPage.login({ email: "user@test.com", password: "pass123" });

      await expect(page).toHaveURL("/dashboard");
    }
  );
});

### E2E Tests: {Feature Name}

**Suite ID:** `{SUITE-ID}`
**Feature:** {Feature description}

---

## Test Case: `{TEST-ID}` - {Test case title}

**Priority:** `{critical|high|medium|low}`

**Tags:**
- type → @e2e
- feature → @{feature-name}

**Description/Objective:** {Brief description}

**Preconditions:**
- {Prerequisites for test to run}
- {Required data or state}

### Flow Steps:
1. {Step 1}
2. {Step 2}
3. {Step 3}

### Expected Result:
- {Expected outcome 1}
- {Expected outcome 2}

### Key verification points:
- {Assertion 1}
- {Assertion 2}

### Notes:
- {Additional considerations}

// auth.setup.ts - Run once, reuse across tests
import { test as setup } from "@playwright/test";

setup("authenticate", async ({ page }) => {
  await page.goto("/login");
  await page.getByLabel("Email").fill("user@test.com");
  await page.getByLabel("Password").fill("password");
  await page.getByRole("button", { name: "Sign in" }).click();
  await page.waitForURL("/dashboard");
  await page.context().storageState({ path: ".auth/user.json" });
});

// playwright.config.ts
projects: [
  { name: "auth", testMatch: /auth\.setup\.ts/ },
  { name: "logged-in", dependencies: ["auth"], use: { storageState: ".auth/user.json" } },
  { name: "logged-out", use: { storageState: { cookies: [], origins: [] } } }
]

// Mock API responses for isolated tests
await page.route("**/api/users", route =>
  route.fulfill({ json: { users: [{ id: 1, name: "Test" }] } })
);

// Mock error states
await page.route("**/api/submit", route =>
  route.fulfill({ status: 500, json: { error: "Server error" } })
);

// Abort requests (e.g., block analytics)
await page.route("**/analytics/**", route => route.abort());

// fixtures.ts - Custom fixtures for setup/teardown
import { test as base } from "@playwright/test";
import { AdminPage } from "./admin/admin-page";

export const test = base.extend<{ adminPage: AdminPage }>({
  adminPage: async ({ page }, use) => {
    const admin = new AdminPage(page);
    await admin.goto();
    await use(admin);
    // Teardown runs after test
  },
});

// Usage in tests
test("admin can manage users", async ({ adminPage }) => {
  await adminPage.deleteUser("test@example.com");
});

// Tests run in parallel by default. Use serial when tests share state:
test.describe.configure({ mode: "serial" });

// Isolate test data to prevent conflicts
test("create user", async ({ page }) => {
  const uniqueEmail = `user-${Date.now()}@test.com`; // ✅ Unique per run
});

// Soft assertions - collect multiple failures
await expect.soft(page.getByText("Title")).toBeVisible();
await expect.soft(page.getByText("Subtitle")).toBeVisible();
// Test continues, reports all failures at end

// Polling assertions - retry until condition met
await expect(async () => {
  const count = await page.getByRole("listitem").count();
  expect(count).toBeGreaterThan(5);
}).toPass({ timeout: 10000 });

// Visual regression
await expect(page).toHaveScreenshot("dashboard.png");
await expect(page.getByRole("dialog")).toHaveScreenshot();

// ❌ Element detached after navigation
const button = page.getByRole("button", { name: "Submit" });
await button.click();
await button.click(); // May fail if page navigated

// ✅ Re-query after navigation
await page.getByRole("button", { name: "Submit" }).click();
await page.getByRole("button", { name: "Confirm" }).click();

// ❌ Race condition with animations
await element.click();

// ✅ Wait for animation to complete
await element.click();
await expect(modal).toBeVisible();

// Iframes
const frame = page.frameLocator("#iframe-id");
await frame.getByRole("button").click();

// Shadow DOM - Playwright pierces by default, but for closed shadow:
await page.locator("custom-element").locator("internal:shadow=button").click();

// In test file
test.use({ viewport: { width: 375, height: 667 } });

// Device emulation
import { devices } from "@playwright/test";
test.use({ ...devices["iPhone 13"] });

// Or in playwright.config.ts projects
projects: [
  { name: "desktop", use: { viewport: { width: 1280, height: 720 } } },
  { name: "mobile", use: { ...devices["iPhone 13"] } },
]

# Enable traces on failure (recommended for CI)
npx playwright test --trace on-first-retry

# View trace file
npx playwright show-trace trace.zip

# Debug mode - step through test
npx playwright test --debug

# Headed mode to see browser
npx playwright test --headed

// In playwright.config.ts
use: {
  trace: "on-first-retry",      // Capture trace on retry
  screenshot: "only-on-failure", // Screenshot on failure
  video: "retain-on-failure",    // Video on failure
}

// playwright.config.ts for CI
export default defineConfig({
  retries: process.env.CI ? 2 : 0,
  workers: process.env.CI ? 1 : undefined,
  reporter: process.env.CI
    ? [["html"], ["github"], ["junit", { outputFile: "results.xml" }]]
    : [["html"]],
  use: {
    trace: "on-first-retry",
    screenshot: "only-on-failure",
  },
});

# GitHub Actions example
- name: Run Playwright tests
  run: npx playwright test
- uses: actions/upload-artifact@v4
  if: always()
  with:
    name: playwright-report
    path: playwright-report/

# Run ALL tests
npx playwright test

# ✅ PREFERRED: Run specific file
npx playwright test tests/login/login.spec.ts

# ✅ PREFERRED: Run specific folder
npx playwright test tests/login/

# ✅ PREFERRED: Run by test name (grep)
npx playwright test --grep "login"
npx playwright test --grep "user can sign up"

# ✅ PREFERRED: Run by tag
npx playwright test --grep "@critical"
npx playwright test --grep "@LOGIN-E2E-001"

# ✅ Run single test by line number
npx playwright test tests/login/login.spec.ts:42

# ✅ Run tests matching multiple patterns
npx playwright test --grep "login|signup"

# ✅ Exclude tests by pattern
npx playwright test --grep-invert "slow"

npx playwright test --debug            # Debug mode (step through)
npx playwright test --headed           # See browser
npx playwright test --trace on         # Enable tracing
npx playwright test --project=mobile   # Run specific project
npx playwright codegen                 # Record tests

// ❌ FRAGILE: Exact string matches break easily
await expect(page.getByText("Welcome to Our Application!")).toBeVisible();
await expect(page.getByRole("button", { name: "Submit Form" })).toBeVisible();
await expect(notification).toHaveText("Your account has been created successfully.");

// ✅ ROBUST: Partial matches survive copy changes
await expect(page.getByText(/welcome/i)).toBeVisible();
await expect(page.getByRole("button", { name: /submit/i })).toBeVisible();
await expect(notification).toContainText("account");
await expect(notification).toContainText(/created/i);

// ✅ ROBUST: Use toContainText over toHaveText
await expect(page.locator(".message")).toContainText("success");

// ✅ ROBUST: Pattern matching for dynamic content
await expect(page.getByText(/order #\d+/i)).toBeVisible();
await expect(page.getByText(/\d+ items? in cart/i)).toBeVisible();